LAWRENCE, Kan. - Whatever slim chance Oklahoma might have had against No. 3 Kansas on Monday night evaporated 5 minutes into the game when Blake Griffin went up for a rebound and "came down kind of funny."

The rest of the night, the Sooners' 6-foot-10 freshman standout looked on glumly from the bench with an ice pack on his left knee as the Jayhawks cruised to an 85-55 victory, hanging with No. 1 North Carolina and No. 2 Memphis as the only unbeatens in Division I.

Darnell Jackson had 17 points and eight rebounds and Brandon Rush had 16 points and nine rebounds for the Jayhawks (17-0, 2-0 Big 12), who have won 31 of their last 32 games and are off to their best start since the 1996-97 team began 22-0.

Griffin, the Big 12's freshman of the week after scoring 53 points in his last two games, hobbled to the bench and then to the locker room with what coach Jeff Capel said was a sprained knee. He was to undergo an MRI on Tuesday.

Without Griffin, the Sooners (12-5, 0-2) were missing their leader in scoring, rebounding and steals and looked hopelessly outmanned against a deep and talented Kansas team that's hardly been challenged so far this season, let alone defeated.

"I don't know if it sealed the deal," Kansas coach Bill Self said, "but I'm sure that deflated them right there. We didn't get their best shot."

Griffin said he went up for a rebound and then felt he knee pop.

"I was just trying to go up for a rebound. I kind of got pushed and I came down wrong. I twisted it or something," he said. "At first, it hurt a lot. When I got back to the locker room it did not hurt that bad."

Jackson, who began the game with a huge dunk off the opening tip, was disappointed Griffin went out.

"I was looking forward to playing against him," Jackson said. "I hope he gets well because he's a great player. We told ourselves we would go out there and play hard no matter what."

Trailing 40-20 at halftime, the Sooners opened the second half with a 5-0 run. But Mario Chalmers scored six straight points in an 11-0 run capped by Rush's fourth 3-pointer, and Oklahoma called a timeout with 16:32 left and the Jayhawks leading 51-25.

"We got off to a better start in the second half with that quick 5-0 run, but then we got into taking some bad shots. Kansas is tremendous," Capel said. "They are going to be a tough team for anyone to beat."

Longar Longar had 21 points for the Sooners, hitting double figures for the eighth time in nine games, but could not stop Kansas from putting its biggest whipping on Oklahoma since a 91-61 victory in 1978.

Darrell Arthur had 14 points and Chalmers added 13 for Kansas, which shot 53 percent against an Oklahoma defense which had been holding opponents to 39 percent. The Sooners were 21-of-64 from the field (33 percent). Without Griffin, they were outrebounded 40-31 by Kansas' deep frontcourt.

Making Griffin's loss even worse for the Sooners is the absence of backup Keith Clark, who has been declared academically ineligible. Oklahoma was forced to play walk-on Beau Gerber.

Kansas took a big early lead and already seemed to have full command of the game when Griffin went out. A few minutes later, David Godbold's 3-pointer sliced the lead to 23-14. But the Jayhawks went on a 10-0 run. Arthur hit four straight free throws to kick-start the spree and Jackson pulled down two rebounds and Sherron Collins had two straight buckets, capping the run with a jumper from the top of the key for a 35-16 lead with 3:17 left.

"We outhustled and outrebounded them," said Rush, a 6-foot-6 junior who has scored 35 points in the last two games. "We played our type of game."

Oklahoma has a good perspective on the three nation's unbeaten teams, having played two of them. The Sooners lost to No. 2 Memphis 63-53 on Nov. 15.

"I think (the Jayhawks) are better," Capel said. "They are the best team we've played and we have played some really good teams. They are so balanced. They shoot better than Memphis. They are bigger. They are probably equally as good in transition but this team passes the ball better.